1848.] LONSDALE ON FOS&IL ZOOPHYTES. 65 



corals — a point not unworthy of attention in attempting to ascertain 

 the natural kingdom to which a spongoid body belonged. 



The reticulated fibres were not visible, except in transparent slices, 

 and not always in such sections. They were most conspicuous in 

 some of the larger lacunae or channels, and where the opacity of the 

 interspaces was least (fig. 4) ; but they were also detectable in the 

 denser portions. Under a power just snfficient to render them visible, 

 the fibres appeared like dark reticulated filaments ; but even in that 

 apparent condition, bright points or lines were discernible in their 

 substance, and they became more marked with a higher magnifier. 

 How far those appearances were due to optical illusion no opinion is 

 hazarded ; but of the existence of a delicate fibrous reticulation, in- 

 dependent of the general calcareous matter, there was seemingly good 

 evidence. It was further inferred, that the reticulations were not 

 liorizontal extensions of tubuli connected with the minor pores, as 

 they ranged across the less-clouded large lacunee, and had an inde- 

 pendent composition ; whereas the pores appeared to be simple per- 

 forations in the calcareous matter. The true nature of the network 

 is, however, left for the development of more competent observers. 



The minor pores (fig. 2), one of the most interesting structures in 

 Amorphozoa, were detectable by a Codrington lens in external sur- 

 faces. Whether they penetrated inwardly, in a direct or tortuous 

 course, no good evidence was obtained ; nor if they communicated 

 with the large lacunse. Thin slices on glass, when viewed with the 

 higher powers of a Hooker's microscope, armed with a plated reflector, 

 exhibited very many translucent or transparent specks, not referable 

 to accidental abrasions, being often well-defined, and they were con- 

 sidered as internal extensions of the pores detectable on the surface. 

 So far as the very limited knowledge of the observer justified a con- 

 clusion, those microscopic channels resembled much more the im- 

 bibing pores of mineral than of corneous sponges, and those of Grantise 

 rather than of Halichondriae. 



The lacunae, believed to have performed the functions of excurrent 

 canals in sponges, presented on the surface, as before stated, irregular 

 pits (fig. 2), often perfectly circumscribed with clear surrounding- 

 areas ; but they were occasionally united by shallow furrows. Inter- 

 nally their existence was abundantly shown, both in polished sections 

 and thin slices (fig. 3), as well as in rough fractures ; but it was not 

 ascertained whether they preserved, in their inward course, an undi- 

 vided character, or were branched. Though in general very nume- 

 rous, they were occasionally less plentiful and small, and in some 

 portions wanting ; but the difference in size, as well as the total 

 absence, was ascribed to progressive fiUing-up as the growth of a 

 specimen rendered them of less importance or unnecessary in those 

 portions, and not to primary conditions of development. Their trans- 

 verse outline (fig. 3) was very irregular, and it had no definite boun- 

 dary, the margin being clearly formed of the fine granular matter 

 which penetrated more or less within their area ; and often a gradually- 

 increased opakeness was shown, according as the eye ranged from 

 the open channel. The reticulated structure was frequently very 



VOL. V. PART I. F 



